It is well known to provide petrol cans to motorists or individuals wishing to transport petrol from a petrol pump to any kind of motorised vehicle, such as a lawnmower, tractor and occasionally to a broken down car. Emergency breakdown services occasionally carry cans full of fuel for refuelling motorists who have run out of fuel away from home. Known fuel cans generally have a single opening through which liquid may be poured into or out of the container and a separately attachable spout for attachment to the opening as an extension, to pour the liquid more directly into the fuel tank of the vehicle. There is a need for an improved closure device for such containers to simplify the transition from a sealed transporting configuration into an open, pouring, configuration of the container. Such closures can also be useful in other areas where fluids are temporarily transported in containers and where it is desired to facilitate fast, convenient, safe and controlled release of the fluid from the container.